The present invention relates to the field of protective coverings, and more particularly to cartridges containing information storage and retrieval medium, and even more particularly to optical information recording disks.
Due to the delicate nature of the surfaces of magnetic and optical information storage media, a wide selection of means have been developed for protecting such media. Since the potential for damage is much greater for media which is used in a device having removable recording structures, primary effort has been directed to protecting such removable media. The integrity of such removable media is jeopardized in two different ways. The first is by exposure to the open atmosphere which presents the risk of contact with hostile contaminates. The second is by physical damage, which is an ever present risk due to the handling which occurs during loading and unloading operations.
In the more sophisticated computer equipment, presently in use and being developed, having significantly higher concentrations of data bit densities, attempts to preserve and protect said recording media integrity have included not only improved protective cassettes and cartridges with effort directed toward automatic loading and unloading devices, but also the incorporation of sophisticated air filter systems into the device to remove contaminates from the air to which the media is exposed. However, the advent of optical information recording has presented even greater new challenges in the area of recording medium integrity and protection. First, because optical information for recording is transmitted through free space, and secondly, because optical information may be recorded at a density that is several orders of magnitude denser than that achievable with magnetic recording media. Thus, the effect of random dust particles and other hostile contaminates, as well as casual damage to the recording medium, also increases by several orders of magnitude as the density or recorded bit population increases.
What is needed, therefore, is a protective cartridge for encapsulating information storage media which is hermetically sealed and in which the information storage medium may reside in a contaminate free state. In addition, the cartridge should provide substantial protection against physical abuse and damage of the recording medium contained therein.